Disk/pad clean with wafer and wafer edge/bevel clean module for chemical mechanical polishing

ABSTRACT

A method and apparatus for cleaning a substrate after chemical mechanical planarizing (CMP) is provided. The apparatus comprises a housing, a substrate holder rotatable on a first axis and configured to retain a substrate in a substantially vertical orientation, a first pad holder having a pad retaining surface facing the substrate holder in a parallel and space apart relation, the first pad holder rotatable on a second axis rotatable parallel to the first axis, a first actuator operable to move the pad holder relative to the substrate holder to change a distance defined between the first axis and the second axis, and a second pad holder disposed in the housing, the second pad holder having a pad retaining surface facing the substrate holder in a parallel and spaced apart relation, wherein the second pad holder is couple with a rotary arm.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. Provisional Patent ApplicationSer. No. 61/794,875, filed Mar. 15, 2013, which is herein incorporatedby reference in its entirety.

BACKGROUND

Field

Implementations of the present invention relate to a method andapparatus for cleaning a substrate after chemical mechanical planarizing(CMP).

Description of the Related Art

In the process of fabricating modern semiconductor integrated circuits(ICs), it is often necessary to planarize surfaces prior to depositingsubsequent layers to ensure accurate formation of photoresist masks andto maintain stack tolerances. One method for planarizing a layer duringIC fabrication is chemical mechanical planarizing (CMP). In general, CMPinvolves the relative movement of the substrate held in a polishing headagainst a polishing material to remove surface irregularities from thesubstrate. In a CMP process, the polishing material is wetted with apolishing fluid that may contain at least one of an abrasive or chemicalpolishing composition. This process may be electrically assisted toelectrochemically planarize conductive material on the substrate.

Planarizing hard materials such as oxides typically requires that thepolishing fluid or the polishing material itself include abrasives. Asthe abrasives often cling or become partially embedded in the layer ofmaterial being polished, the substrate is processed on a buffing moduleto remove the abrasives from the polished layer. The buffing moduleremoves the abrasives and polishing fluid used during the CMP process bymoving the substrate which is still retained in the polishing headagainst a buffing material in the presence of deionized water orchemical solutions. The buffing module is substantially identical to theCMP module except for the polishing fluids utilized and the material onwhich the substrate is processed.

Once buffed, the substrate is transferred to a series of cleaningmodules that further remove any remaining abrasive particles and/orother contaminants that cling to the substrate after the planarizing andbuffing process before they can harden on the substrate and createdefects. The cleaning modules may include, for example, a megasoniccleaner, a scrubber or scrubbers, and a dryer. The cleaning modules thatsupport the substrates in a vertical orientation are especiallyadvantageous, as they also utilize gravity to enhance removal ofparticles during the cleaning process, and are also typically morecompact.

Although present CMP processes have been shown to be robust and reliablesystems, the configuration of the system equipment requires the buffingmodule to utilize critical space which could alternatively be utilizedfor additional CMP modules. However, certain polishing fluids, forexample those using cerium oxide, are particularly difficult to removeand conventionally require processing the substrate in buffing modulebefore being transferred to the cleaning module as conventional cleaningmodules have not demonstrated the ability to satisfactorily removeabrasive particles from oxide surfaces that have not been buffed priorto cleaning.

Therefore, there is a need in the art for an improved CMP process andcleaning module.

SUMMARY

Implementations of the present invention relate to a method andapparatus for cleaning a substrate after chemical mechanical planarizing(CMP). In one implementation, a particle cleaning module is provided.The particle cleaning module comprises a housing, a substrate holderdisposed in the housing, the substrate holder configured to retain asubstrate in a substantially vertical orientation, the substrate holderrotatable on a first axis, a first pad holder disposed in the housing,the first pad holder having a pad retaining surface facing the substrateholder in a parallel and space apart relation, the first pad holderrotatable on a second axis rotatable parallel to the first axis, a firstactuator operable to move the first pad holder relative to the substrateholder to change a distance defined between the first axis and thesecond axis, and a second pad holder disposed in the housing, the secondpad holder having a pad retaining surface facing the substrate holder ina parallel and spaced apart relation, the second pad holder rotatable ona third axis parallel to the first axis and the second axis.

In one implementation, a particle cleaning module is provided. Theparticle cleaning module comprises a housing, a substrate holderdisposed in the housing, a first pad holder disposed in the housing, asecond pad holder disposed in the housing and a rotary arm assembly. Thesubstrate holder is configured to retain a substrate in a substantiallyvertical orientation and the substrate holder rotatable on a first axis.The first pad holder has a pad retaining surface facing the substrateholder in a parallel and spaced apart relation, the first pad holderrotatable on a second axis rotatable parallel to the first axis. A firstactuator operable to move the first pad holder relative to the substrateholder to change a distance defined between the first axis and thesecond axis. The second pad holder has a pad retaining surface facingthe substrate holder in a parallel and spaced apart relation, the secondpad holder rotatable on a third axis parallel to the first axis and thesecond axis. The rotary arm assembly comprises a rotary arm coupled withthe second pad holder and operable for sweeping the second pad holderacross the surface of the substrate and a lateral actuator mechanismform moving the rotary arm toward the substrate.

In another implementation, a method for cleaning a substrate isprovided. The method comprises spinning a substrate disposed in avertical orientation, providing a cleaning fluid to a surface of thespinning substrate, pressing a first pad against the spinning substrate,moving the first pad laterally across the substrate, providing apolishing fluid to an edge portion of the spinning substrate, pressing asecond pad against the spinning substrate, and moving the second padlaterally across the edge of the substrate. Pressing the first padagainst the spinning substrate may further comprise spinning the firstpad. Pressing the first pad against the spinning substrate may furthercomprise spinning the first pad. The method may further comprise placingthe substrate in a megasonic cleaning module prior to moving the firstpad laterally across the substrate, placing the substrate in one or morebrush modules after moving the second pad laterally across the edge ofthe substrate and placing the substrate in dryer after placing thesubstrate in the one or more brush modules. The method may furthercomprise planarizing a surface of the substrate prior to placing thesubstrate in the megasonic cleaning module. The method may furthercomprise providing the cleaning fluid to the substrate after moving thefirst pad laterally across the substrate and prior to placing thesubstrate in the one or more brush modules.

In yet another implementation, a method for cleaning a substrate isprovided. The method comprises spinning a substrate disposed in avertical orientation, providing a cleaning fluid to a surface of thespinning substrate, pressing a first pad against the spinning substrate,moving the first pad across the substrate along a curved path, providinga polishing fluid to an exclusion region and/or edge portion of thespinning substrate, pressing a second pad against the spinning substrateand moving the second pad laterally across the edge of the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentinvention can be understood in detail, a more particular description ofthe invention, briefly summarized above, may be had by reference toimplementations, some of which are illustrated in the appended drawings.It is to be noted, however, that the appended drawings illustrate onlytypical implementations of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective implementations.

FIG. 1 is a schematic illustration of a cross-section of a portion of asubstrate;

FIG. 2 illustrates a top view of a semiconductor substrate chemicalmechanical planarization system having a cleaning system which includesone implementation of a particle cleaning module according toimplementations described herein;

FIG. 3 is a front view of cleaning system depicted in FIG. 2 accordingto implementations described herein;

FIG. 4 is a cross-sectional view of the particle cleaning moduledepicted in FIG. 2 according to implementations described herein;

FIG. 5 is a cross-sectional view of the particle cleaning module takenalong the section line 5-5 of FIG. 4 according to implementationsdescribed herein;

FIG. 6 is a cross-sectional view of the particle cleaning module takenalong the section line 6-6 of FIG. 4 according to implementationsdescribed herein;

FIG. 7 is a top view of a pad holder engaging a pad with a substrateretained by the substrate holder within the particle cleaning module ofFIG. 2 according to implementations described herein;

FIG. 8 is a top schematic view of the particle cleaning module having apad conditioning assembly disposed therein;

FIGS. 9A-9C are schematic views of the disk pad holder according toimplementations described herein;

FIGS. 10A-10D are schematic view of the disk pad holder according toimplementations described herein;

FIG. 11 is a schematic cross-sectional view of another implementation ofa particle cleaning module according to implementations describedherein;

FIG. 12 is a cross-sectional schematic view of another implementation ofa disk pad holder according to implementations described herein;

FIG. 13 is another schematic view of the particle cleaning module ofFIG. 11 according to implementations described herein;

FIG. 14 is another schematic view of the particle cleaning module ofFIG. 11 according to implementations described herein;

FIG. 15 is a schematic view of a portion of a particle cleaning moduleillustrating another implementation of a pad conditioning assemblyaccording to implementations described herein; and

FIG. 16 is a schematic view of another implementation of an edge padpolishing assembly according to implementations described herein.

To facilitate understanding, identical reference numerals have beenused, wherever possible, to designate identical elements that are commonto the Figures. Additionally, elements of one implementation may beadvantageously adapted for utilization in other implementationsdescribed herein.

DETAILED DESCRIPTION

Implementations of the present invention relate to a method andapparatus for cleaning a substrate after chemical mechanical planarizing(CMP). More specifically implementations of the present inventionprovide improved methods and apparatus for cleaning and/or polishing theexclusion region and/or edge of a substrate. Abrasive particles (e.g.,cerium oxide (CeO)) used in oxide CMP are difficult to remove usingtraditional PVA brush scrubbing and often require performance of abuffing process on an additional platen on the polishing tool. Howevereven with buffing on the polishing platen particles at the wafer edge(e.g. ≦2 mm) are very difficult to remove.

Certain implementations described herein provide a clean process whereslurry polishing is performed at the exclusion region and/or edge of awafer after particle cleaning. Certain implementations of the currentinvention provide an apparatus where a slurry polishing process at theexclusion region and/or edge of a wafer is implemented without affectingthe polishing performance in the device area. The apparatus, describedbelow as a particle cleaning module, advantageously allows for increasedutilization and throughput of the CMP system, while reducing the amountand cost of consumables needed to effectively clean a substrate asfurther described below.

The particle cleaning module has a wafer chuck which may support a fullwafer size and a disk brush holder with a diameter of less than 50 mm.The wafer chuck speed may be more than 500 rpm and the disk brush holderspeed may be more than 1000 rpm. A soft pad, such as politex typematerial, may be used as a cleaning pad. The cleaning pad may be adheredon top of the disk brush holder with a pressure sensitive adhesive.During the cleaning process, the wafer is rotated by the wafer chuck andthe disk brush with the soft pad rotates and sweeps from the center ofthe wafer to the edge of the wafer or vice versa. The contact pressureand/or gap between the soft pad and the wafer may be controlled by alinear motor. This motion may be repeated several times until theabrasive particles are removed from most of the wafer surface, exceptthe wafer edge at 2 mm edge exclusion. Afterward, a polishing step isperformed where a polishing pad is moved to the edge of the wafer andthe slurry is delivered next to the polishing pad where the wafer andthe pad are rotated and contacted during the polishing. It is desirableto have the polishing pad only polish the exclusion region and/or edgeregion without touching the device region. The polishing pad may rotateat high speed as well as sweep back and forth at the edge of the wafer.In certain implementations it desirable to have separate pads, a firstpad for removing particles from the surface of the wafer and a secondpad for polishing at the wafer edge where a local slurry is delivered.

In certain implementations, the particle cleaning module uses a rotaryarm in place of the lateral linear motion design. The Disk/Pad/Fluid Jetmodule design uses the rotary arm motion concept to control theDisk/Pad/Fluid Jet to scan on the wafer surface. By using the rotary armmotion design, the processing tank sealing and servicing is easier andproduction costs are cheaper than the current lateral linear motionDisk/Pad/Fluid Jet design.

In certain implementations, the particle cleaning module design providesa common design layout for multi-wafer processing. For example, byreplacing the Disk, Pad or Fluid Jet, it can perform many kinds of wafercleaning processes in this common module. The particle cleaning modulealso provides a flexible edge clean disk/pad for wafer edge cleaning andwafer bevel cleaning. The Disk/Pad/Fluid Jet may be moved in and out tocontrol the processing force and distance to wafer surface. The Disk/Padclean pressure force on the wafer may be set from 0˜5 Lb. Further, thewafer vacuum chuck design provides full wafer support for higherDisk/Pad processing force. The wafer gripper design provides waferedge-contact for both sides of the wafer (front and back) duringprocessing and rinsing.

Implementations described herein will be described below in reference toa planarizing process and composition that can be carried out usingchemical mechanical polishing process equipment, such as MIRRA™, MIRRAMESA™, REFLEXION®, REFLEXION LK™, and REFLEXION® GT™ chemical mechanicalplanarizing systems, available from Applied Materials, Inc. of SantaClara, Calif. Other planarizing modules, including those that useprocessing pads, planarizing webs, or a combination thereof, and thosethat move a substrate relative to a planarizing surface in a rotational,linear, or other planar motion may also be adapted to benefit from theimplementations described herein. In addition, any system enablingchemical mechanical polishing using the methods or compositionsdescribed herein can be used to advantage. The following apparatusdescription is illustrative and should not be construed or interpretedas limiting the scope of the implementations described herein.

FIG. 1 is a schematic illustration of a cross-section of a portion of asubstrate 100. With reference to FIG. 1, a substrate 100 may include twomajor surfaces 102 a, 102 b and an edge 104. Each major surface 102 a,102 b of the substrate 100 may include a device region 106 a, 106 b andan exclusion region 108 a, 108 b. (Typically however, only one of thetwo major surfaces 102 a, 102 b will include a device region and anexclusion region.) The exclusion regions 108 a, 108 b may serve asbuffers between the device regions 106 a, 106 b and the edge 104. Theedge 104 of a substrate 100 may include an outer edge 110 and bevels112, 114. The bevels 112, 114 may be located between the outer edge 110and the exclusion regions 108 a, 108 b of the two major surfaces 102 a,102 b. The present invention is adapted to clean and/or polish the outeredge 110 and at least one bevel 112, 114 of a substrate 100 withoutaffecting the device regions 106 a, 106 b. In some implementations, allor part of the exclusion regions 108 a, 108 b may be cleaned or polishedas well.

FIG. 2 illustrates a top view of a semiconductor substrate chemicalmechanical planarization (CMP) system 200 having a cleaning system 216that includes one implementation of a particle cleaning module 282 ofthe present invention. Although the exemplary configurations areprovided for the CMP system 200 and cleaning system 216 in FIG. 2, it iscontemplated that implementations of the particle cleaning module 282 ofthe present invention may be utilized alone, or with cleaning systemshaving alternative configurations and/or CMP systems having alternativeconfigurations.

In addition to the cleaning system 216, the exemplary CMP system 200generally includes a factory interface 202, a loading robot 204, and aplanarizing module 206. The loading robot 204 is disposed proximate thefactory interface 202 and the planarizing module 206 to facilitate thetransfer of substrates 100 therebetween.

A controller 208 is provided to facilitate control and integration ofthe modules of the CMP system 200. The controller 208 comprises acentral processing unit (CPU) 210, a memory 212 and support circuits214. The controller 208 is coupled to the various components of the CMPsystem 200 to facilitate control of, for example, the planarizingcleaning and transfer processes.

The factory interface 202 generally includes an interface robot 220 andone or more substrate cassettes 218. The interface robot 220 is employedto transfer substrates 100 between the substrate cassettes 218, thecleaning system 216 and an input module 224. The input module 224 ispositioned to facilitate transfer of substrates 100 between theplanarizing module 206 and the factory interface 202 as will be furtherdescribed below.

Optionally, polished substrates exiting the cleaning system 216 may betested in a metrology system 280 disposed in the factory interface 202.The metrology system 280 may include an optical measuring device, suchas the NovaScan 420, available from Nova Measuring Instruments, Inc.located in Sunnyvale, Calif. The metrology system 280 may include abuffer station (not shown) for facilitating entry and egress ofsubstrates from the optical measuring device or other metrology device.One such suitable buffer is described in U.S. Pat. No. 6,244,931, issuedJun. 12, 2001 to Pinson, et al.

The planarizing module 206 includes at least one CMP station. It iscontemplated that the CMP station maybe configured as an electrochemicalmechanical planarizing station. In the implementation depicted in FIG.2, the planarizing module 206 includes a plurality of CMP stations,illustrated as a first station 228, a second station 230 and a thirdstation 232 disposed in an environmentally controlled enclosure 288. Thefirst station 228 includes a conventional CMP station configured toperform an oxide planarization process utilizing an abrasive containingpolishing fluid. It is contemplated that CMP processes to planarizedother materials may be alternatively performed, including the use ofother types of polishing fluids. As the CMP process is conventional innature, further description thereof has been omitted for the sake ofbrevity. The second station 230 and the third station 232 will bediscussed in detail further below.

The exemplary planarizing module 206 also includes a transfer station236 and a carousel 234 that are disposed on an upper or first side 238of a machine base 240. In one implementation, the transfer station 236includes an input buffer station 242, an output buffer station 244, atransfer robot 246 and a load cup assembly 248. The loading robot 204 isconfigured to retrieve substrates from the input module 224 and transferthe substrates to the input buffer station 242. The loading robot 204 isalso utilized to return polished substrates from the output bufferstation 244 to the input module 224, from where the polished substratesare then advanced through the cleaning system 216 prior to beingreturned to the substrate cassettes 218 coupled to the factory interface202 by the interface robot 220. The transfer robot 246 is utilized tomove substrates between the buffer stations 242, 244 and the load cupassembly 248.

In one implementation, the transfer robot 246 includes two gripperassemblies, each having pneumatic gripper fingers that hold thesubstrate by the substrate's edge. The transfer robot 246 maysimultaneously transfer a substrate to be processed from the inputbuffer station 242 to the load cup assembly 248 while transferring aprocessed substrate from the load cup assembly 248 to the output bufferstation 244. An example of a transfer station that may be used toadvantage is described in United States Patent Application No.6,156,124, issued Dec. 5, 2000 to Tobin.

The carousel 234 is centrally disposed on the machine base 240. Thecarousel 234 typically includes a plurality of arms 250, each supportinga polishing head assembly 252. Two of the arms 250 depicted in FIG. 2are shown in phantom such that a planarizing surface of a polishing pad226 of the first station 228 and the transfer station 236 may be seen.The carousel 234 is indexable such that the polishing head assemblies252 may be moved between the planarizing stations 228, 230, 232 and thetransfer station 236. One carousel that may be utilized to advantage isdescribed in U.S. Pat. No. 5,804,507, issued Sep. 8, 1998 to Perlov, etal.

The cleaning system 216 removes polishing debris, abrasives, polishingfluid, and/or excess deposited material from the polished substratesthat remains after polishing. The cleaning system 216 includes aplurality of cleaning modules 260, a substrate handler 266, a dryer 262and an output module 256. The substrate handler 266 retrieves aprocessed substrate 100 returning from the planarizing module 206 fromthe input module 224 and transfers the substrate 100 through theplurality of cleaning modules 260 and dryer 262. The dryer 262 driessubstrates exiting the cleaning system 216 and facilitates substratetransfer between the cleaning system 216 and the factory interface 202by the interface robot 220. The dryer 262 may be a spin-rinse-dryer orother suitable dryer. One example of a suitable dryer 262 may be foundas part of the MESA™ or Desica® Substrate Cleaners, both available fromApplied Materials, Inc., of Santa Clara, Calif.

In the implementation depicted in FIG. 2, the cleaning modules 260utilized in the cleaning system 216 include a megasonic clearing module264A, the particle cleaning module 282, a first brush module 264B and asecond brush module 264C. However, it is to be appreciated that theparticle cleaning module 282 of the present invention may be used withcleaning systems incorporating one or more modules having one or moretypes of modules. Each of the cleaning modules 260 is configured toprocess a vertically oriented substrate, i.e., one in which the polishedsurface is in a substantially vertical plane. The vertical plane isrepresented by the Y-axis, which is perpendicular to the X-axis andZ-axis shown in FIG. 2. The particle cleaning module 282 will bediscussed in detail further below with reference to FIG. 4.

In operation, the CMP system 200 is initiated with the substrate 100being transferred from one of the substrate cassettes 218 to the inputmodule 224 by the interface robot 220. The loading robot 204 then movesthe substrate from the input module 224 to the transfer station 236 ofthe planarizing module 206. The substrate 100 is loaded into thepolishing head assembly 252 moved over and polished against thepolishing pad 226 while in a horizontal orientation. Once the substrateis polished, polished substrates 100 are returned to the transferstation 236 from where the loading robot 204 may transfer the substrate100 from the planarizing module 206 to the input module 224 whilerotating the substrate to a vertical orientation. The substrate handler266 then retrieves the substrate from the input module 224 transfers thesubstrate through the cleaning modules 260 of the cleaning system 216.Each of the cleaning modules 260 is adapted to support a substrate in avertical orientation throughout the cleaning process. Once cleaned, thecleaned substrate 100 is to the output module 256. The cleaned substrate100 is returned to one of the substrate cassettes 218 by the interfacerobot 220 while returning the cleaned substrate 100 to a horizontalorientation. Optionally, the interface robot 220 may transfer thecleaned substrate to the metrology system 280 prior to the substrate'sreturn to one of the substrate cassettes 218.

Although any suitable substrate handler may be utilized, the substratehandler 266 depicted in FIG. 2 includes a robot 268 having at least onesubstrate gripper (two substrate grippers 274, 276 are shown) that isconfigured to transfer substrates between the input module 224, thecleaning modules 260 and the dryer 262. Optionally, the substratehandler 266 may include a second robot (not shown) configured totransfer the substrate between the last cleaning module 260 and thedryer 262 to reduce cross contamination.

In the implementation depicted in FIG. 2, the substrate handler 266includes a rail 272 coupled to a partition 258 separating the substratecassettes 218 and interface robot 220 from the cleaning system 216. Therobot 268 is configured to move laterally along the rail 272 tofacilitate access to the cleaning modules 260, dryer 262 and the inputand output modules 224, 256.

FIG. 3 depicts a front view of the substrate handler 266 according toone implementation of the invention. The robot 268 of the substratehandler 266 includes a carriage 302, a mounting plate 304 and thesubstrate grippers 274, 276. The carriage 302 is slidably mounted on therail 272 and is driven horizontally by an actuator 306 along a firstaxis of motion A₁ defined by the rail 272 which is parallel to theZ-axis. The actuator 306 includes a motor 308 coupled to a belt 310. Thecarriage 302 is attached to the belt 310. As the motor 308 advances thebelt 310 around the sheave 312 positioned at one end of the cleaningsystem 216, the carriage 302 moves along the rail 272 to selectivelyposition the robot 268. The motor 308 may include an encoder (not shown)to assist in accurately positioning the robot 268 over the input andoutput modules 224, 256 and the various cleaning modules 260.Alternatively, the actuator 306 may be any form of a rotary or linearactuator capable of controlling the position of the carriage 302 alongthe rail 272. In one implementation, the carriage 302 is driven by alinear actuator having a belt drive, such as the GL15B linear actuatorcommercially available from THK Co., Ltd. located in Tokyo, Japan.

The mounting plate 304 is coupled to the carriage first 302. Themounting plate 304 includes at least two parallel tracks 316A-B alongwhich the positions of the substrate grippers 274, 276 are independentlyactuated along a second and third axes of motion A₂, A₃. The second andthird axes of motion A₂, A₃ are oriented perpendicular to the first axisA₁ and are parallel to the Y-axis.

FIG. 4 depicts a cross-sectional view of the particle cleaning module282 of FIG. 2. The particle cleaning module 282 includes a housing 402,a substrate rotation assembly 404, a first pad actuation assembly 406and a second pad actuation assembly 470. Although a first pad actuationassembly 406 and a second pad actuation assembly 470 are shown, itshould be understood that the implementations described herein may beperformed with a single pad actuation assembly. For example, the firstpad actuation assembly 406 and the second pad actuation assembly 470 maybe positioned in separate housings. The housing 402 includes an opening408 at a top of the housing and a substrate receiver 410 at a bottom 418of the housing. A drain 468 is formed through the bottom 418 of thehousing 402 to allow fluids to be removed from the housing 402. Theopening 408 allows the robot 268 (not shown in FIG. 4) to verticallytransfer the substrate to an internal volume 412 defined within thehousing 402. The housing 402 may optionally include a lid 430 that canopen and close to allow the robot 268 in and out of the housing 402.

The substrate receiver 410 has a substrate receiving slot 432 facingupwards parallel to the Y-axis. The substrate receiving slot 432 issized to accept the perimeter of the substrate 100, thereby allowing theone of the substrate grippers 274, 276 of the substrate handler 266 toplace the substrate 100 in the substrate receiving slot 432 in asubstantially vertical orientation. The substrate receiver 410 iscoupled to a Z-Y actuator 411. The Z-Y actuator 411 may be actuated tomove the substrate receiver 410 upwards in the Y-axis to align acenterline of the substrate 100 disposed in the substrate receiver 410with a centerline of the substrate rotation assembly 404. Once thecenterline of the substrate 100 is aligned with the centerline of thesubstrate rotation assembly 404, the Z-Y actuator 411 may be actuated tomove the substrate receiver 410 in the Z-axis to contact the substrate100 against the substrate rotation assembly 404, which then actuates tochuck the substrate 100 to the substrate rotation assembly 404. Afterthe substrate 100 has been chucked to the substrate rotation assembly404, the Z-Y actuator 411 may be actuated to move the substrate receiver410 in the Y-axis clear of the substrate 100 and the substrate rotationassembly 404 so that the substrate 100 held by the substrate rotationassembly 404 may be rotated without contacting the substrate receiver410.

The substrate rotation assembly 404 is disposed in the housing 402 andincludes a substrate holder 414 coupled to a substrate rotationmechanism 416. The substrate holder 414 may be an electrostatic chuck, avacuum chuck, a mechanical gripper or any other suitable mechanism forsecurely holding the substrate 100 while the substrate is rotated duringprocessing within the particle cleaning module 282. Preferably, thesubstrate holder 414 is either an electrostatic chuck or a vacuum chuck.

FIG. 5 is a cross-sectional view of the particle cleaning module 282taken along the section line 5-5 of FIG. 4 thus illustrating a face 504of the substrate holder 414. Referring to both FIG. 4 and FIG. 5, theface 504 of the substrate holder 414 includes one or more apertures 502fluidly coupled to a vacuum source 497. The vacuum source 497 isoperable to apply a vacuum between the substrate 100 and the substrateholder 414, thereby securing the substrate 100 and the substrate holder414. Once the substrate 100 is held by the substrate holder 414, thesubstrate receiver 410 moves downward in a vertical direction parallelto the Y-axis towards the bottom 418 of the housing 402 to be clear ofthe substrate, as seen in FIG. 5. The substrate receiver 410 may move ina horizontal direction towards an edge 420 of the housing 402 to befurther clear of the substrate.

The substrate holder 414 is coupled to the substrate rotation mechanism416 by a first shaft 423 that extends through a hole 424 formed throughthe housing 402. The hole 424 may optionally include sealing members 426to provide a seal between the first shaft 423 and the housing 402. Thesubstrate holder 414 is controllably rotated by the substrate rotationmechanism 416. The substrate rotation mechanism 416 may be an electricalmotor, an air motor, or any other motor suitable for rotating thesubstrate holder 414 and substrate 100 chucked thereto. The substraterotation mechanism 416 is coupled to the controller 208. In operation,the substrate rotation mechanism 416 rotates the first shaft 423, whichrotates the substrate holder 414 and the substrate 100 secured thereto.In one implementation the substrate rotation mechanism 416 rotates thesubstrate holder 414 (and substrate 100) at a rate of at least 500revolutions per minute (rpm).

The first pad actuation assembly 406 includes a pad rotation mechanism436, a pad cleaning head 438, and a lateral actuator mechanism 442. Thepad cleaning head 438 is located in the internal volume 412 of thehousing 402 and includes a first pad holder 434 that holds a pad 444 anda fluid delivery nozzle 450. The fluid delivery nozzle 450 is coupled toa fluid delivery source 498 that provides deionized water, a chemicalsolution or any other suitable fluid to the pad 444 during cleaning thesubstrate 100. The lid 430 may be moved to a position that closes theopening 408 of the housing 402 above the fluid delivery nozzle 450 toprevent fluids from being spun out of the housing 402 during processing.

A centerline of the first pad holder 434 may be aligned with thecenterline of the substrate holder 414. The first pad holder 434 (andpad 444) has a diameter much less than that of the substrate 100, forexample at least less than half the diameter of the substrate or even asmuch as less than about one eighth the diameter of the substrate. In oneimplementation, the first pad holder 434 (and pad 444) may have adiameter of less than about 25 mm. The first pad holder 434 may holdsthe pad 444 utilizing clamps, vacuum, adhesive or other suitabletechnique that allows for the pad 444 to periodically be replaced as thepad 444 becomes worn after cleaning a number of substrates 100.

The pad 444 may be fabricated from a polymer material, such as porousrubber, polyurethane and the like, for example, a POLYTEX™ pad availablefrom Rodel, Inc, of Newark, Del. In one implementation, the pad holder434 may be used to a hold a brush or any other suitable cleaning device.The first pad holder 434 is coupled to the pad rotation mechanism 436 bya second shaft 446. The second shaft 446 is oriented parallel to theZ-axis and extends from the internal volume 412 through an elongatedslit formed through the housing 402 to the pad rotation mechanism 436.The pad rotation mechanism 436 may be an electrical motor, an air motor,or any other suitable motor for rotating the first pad holder 434 andpad 444 against the substrate. The pad rotation mechanism 436 is coupledto the controller 208. In one implementation, the pad rotation mechanism436 rotates the first pad holder 434 (and pad 444) at a rate of at leastabout 1000 rpm.

The pad rotation mechanism 436 is coupled to bracket 454 by an axialactuator 440. The axial actuator 440 is coupled to the controller 208 orother suitable controller and is operable to move the first pad holder434 along the Z-axis to move the pad 444 against and clear of thesubstrate 100 held by the substrate holder 414. The axial actuator 440may be a pancake cylinder, linear actuator or any other suitablemechanism for moving the first pad holder 434 in a direction parallel tothe Z-axis. In operation, after the substrate holder 414 is in contactwith and holding the substrate, the axial actuator 440 drives the firstpad holder 434 in a z-direction to make contact with the substrate 100.

The bracket 454 is coupled to a base 462 by the lateral actuatormechanism 442 by a carriage 456 and rail 458 that allows the padcleaning head 438 to move laterally in a direction parallel to theX-axis, as depicted in FIG. 6. The carriage 456 is slidably mounted onthe rail 458 and is driven horizontally by the lateral actuatormechanism 442 to scan the pad 444 across the substrate 100. The lateralactuator mechanism 442 may be a lead screw, a linear actuator or anyother suitable mechanism for moving the pad cleaning head 438horizontally. The lateral actuator mechanism 442 is coupled tocontroller 208 or other suitable controller.

The second pad actuation assembly 470 includes a pad rotation mechanism472, a pad polishing head 474, and a lateral actuator mechanism 476. Thepad polishing head 474 is located in the internal volume 412 of thehousing 402 and includes a second pad holder 478 that holds a polishingpad 480 and a fluid delivery nozzle 482. The fluid delivery nozzle 450is coupled to a fluid delivery source 484 that provides polishingslurry, deionized water, a chemical solution or any other suitable fluidto the polishing pad 480 during polishing of the exclusion region and/oredge region of the substrate 100. The lid 430 may be moved to a positionthat closes the opening 408 of the housing 402 above the fluid deliverynozzle 482 to prevent fluids from being spun out of the housing 402during processing.

A centerline of the second pad holder 478 may be aligned with the edgeof the substrate 100. The second pad holder 478 (and polishing pad 480)has a diameter much less than that of the substrate 100, for example atleast less than half the diameter of the substrate or even as much asless than about one eighth the diameter of the substrate. In oneimplementation, the second pad holder 478 (and polishing pad 480) mayhave a diameter of less than about 50 mm. The second pad holder 478 mayhold the polishing pad 480 utilizing clamps, vacuum, adhesive or othersuitable techniques that allow for the polishing pad 480 to periodicallybe replaced as the polishing pad 480 becomes worn after polishing theedge of a number of substrates 100.

The polishing pad 480 may be fabricated from a polymer material, such asporous rubber, polyurethane and the like, for example, a POLYTEX™ padavailable from Rodel, Inc. of Newark, Del. The polishing pad 480 may bea fixed abrasive pad. The second pad holder 478 is coupled to the padrotation mechanism 472 by a third shaft 486. The third shaft 486 isoriented parallel to the Z-axis and extends from the internal volume 412through an elongated slit formed through the housing 402 to the padrotation mechanism 472. The pad rotation mechanism 472 may be anelectrical motor, an air motor, or any other suitable motor for rotatingthe second pad holder 478 and polishing pad 480 against the substrate100. The pad rotation mechanism 472 is coupled to the controller 208. Inone implementation, the pad rotation mechanism 472 rotates the secondpad holder 478 (and polishing pad 480) at a rate of at least about 1000rpm.

The pad rotation mechanism 472 is coupled to bracket 488 by an axialactuator 490. The axial actuator 490 is coupled to the controller 208 orother suitable controller and is operable to move the second pad holder478 along the Z-axis to move the polishing pad 480 against and clear ofthe substrate 100 held by the substrate holder 414. The axial actuator490 may be a pancake cylinder, linear actuator or any other suitablemechanism for moving the second pad holder 478 in a direction parallelto the Z-axis. In operation, after the substrate holder 414 is incontact with and holding the substrate, the axial actuator 490 drivesthe second pad holder 478 in a z-direction to make contact with thesubstrate 100.

The bracket 488 is coupled to a base 492 by the lateral actuatormechanism 476 by a carriage 494 and rail 496 that allows the padpolishing head 474 to move laterally in a direction parallel to theX-axis, as depicted in FIG. 6. The carriage 494 is slidably mounted onthe rail 496 and is driven horizontally by the lateral actuatormechanism 476 to scan the polishing pad 480 across the substrate 100.The lateral actuator mechanism 476 may be a lead screw, a linearactuator or any other suitable mechanism for moving the pad polishinghead 474 horizontally. The lateral actuator mechanism 476 is coupled tocontroller 208 or other suitable controller.

Scanning the pad 444 across the substrate 100 in the particle cleaningmodule 282 has effectively demonstrated the ability to effectivelyremove particles, such as abrasives from the polishing fluid, from thesurface of the substrate 100. Further, scanning the polishing pad 480across the exclusion region and/or edge region has demonstrated theability to effectively remove particles, such as abrasives, excessdeposited material, and/or polishing slurry from the surface of thesubstrate 100, for example, the exclusion region and/or edge region ofthe substrate. Thus, the inclusion of a polishing step at the wafer edgein addition to particle cleaning has effectively demonstrated edgedefect improvement. Accordingly, the need for a dedicated buffingstation on the polishing module is substantially eliminated.

FIG. 7 is a side view of the first pad holder 434 and the second padholder 478 engaging pad 444 and pad 480 respectively with the substrate100 retained by the substrate holder 414. In operation, with respect tothe first pad holder 434, the axial actuator 440 urges the pad 444against the substrate 100 rotated by the substrate rotation mechanism416 while the pad rotation mechanism 436 spins the pad 444. The lateralactuator mechanism 442 moves the first pad holder 434 and pad 444 in ahorizontal direction across the surface of the substrate 100. While thepad 444 is in contact with the substrate 100, the fluid delivery nozzle450 provides at least one of deionized water, a chemical solution or anyother suitable fluid to the surface of the substrate 100 being processedby the pad 444. Accordingly, the pad 444 cleans the surface of thesubstrate with minimal movement.

In operation, with respect to the second pad holder 478, the axialactuator 490 urges the polishing pad 480 against the substrate 100rotated by the substrate rotation mechanism 416 while the pad rotationmechanism 472 spins the polishing pad 480. The lateral actuatormechanism 476 moves the second pad holder 478 and the polishing pad 480in a horizontal direction across the surface of the substrate 100. Whilethe polishing pad 480 is in contact with the exclusion region and/oredge region of the substrate 100, the fluid delivery nozzle 482 providesat least one of polishing slurry, deionized water, a chemical solutionor any other suitable fluid to the surface of the substrate 100 beingprocessed by the polishing pad 480. Accordingly, the pad 444 cleans theedge of the substrate with minimal movement.

It should be understood that although FIG. 7 depicts pad 444 andpolishing pad 480 simultaneously contacting substrate 100, theimplementations described herein do not require simultaneous contact ofthe substrate by the pad 444 and the polishing pad 480. For example, theparticle cleaning process performed by pad 444 may be performedsequentially (e.g., prior to and/or after) with respect to the edgepolishing process performed by polishing pad 480.

One advantage of the invention is the relatively small size of the pads444 and 480 compared to the size of the substrate 100. Conventionalsystems use large pads positioned on the polishing module to cleansmaller substrates, where the substrate is in 100 percent contact withthe pad. Large pads are prone to trapping abrasives and particulateswhich often cause scratches and defects in the substrate. However, thesmaller pad of the present invention is significantly less prone toabrasive and particulate trapping, which advantageously results in acleaner pad and substrates with less scratches and defects.Additionally, the smaller pad of the present invention significantlyreduces the cost of consumables, both in the amount of fluid utilizedduring processing and the cost of replacement pads. Furthermore, thesmaller pad of the present invention significantly allows the pad to beeasily removed or replaced.

Referring back to FIG. 6, once the substrate is cleaned and the edge ofthe substrate has been polished, the pad actuation assemblies 406, 470retract the pad holders 434, 478 and pads 444, 480 away from thesubstrate 100 (shown in phantom). The first pad holder 434 and pad 444may be moved linearly in a direction parallel to the X-axis away fromthe substrate and out of the internal volume 412 of the housing 402 intoa pocket 604 coupled to the housing 402. Positioning the first padholder 434 and pad 444 in the pocket 604 as shown in phantom in FIG. 6and out of the internal volume 412 of the housing 402 advantageouslyprovides more space for the robot 268 to enter the housing 402 andtransfer the substrate without risk of damaging either the pad 444 orthe substrate 100, while allowing the housing 402 to be smaller and lessexpensive.

Substrate transfer begins after cleaning by having the substratereceiver 410 move upward in a direction parallel to the Y-axis to engagethe substrate 100 in the substrate receiving slot 432. Once thesubstrate is disposed in the substrate receiving slot 432, the substrateholder 414 releases the substrate 100 by turning off the vacuum providedby the vacuum source 497, and optionally providing a gas through theapertures 502 of the substrate holder 414 to separate the substrate fromthe substrate holder 414. The substrate receiver 410 with the substrate100 disposed in the substrate receiving slot 432 is then moved laterallyaway from the substrate holder 414 in a direction parallel to the Z-axisto clear the substrate 100 from the substrate holder 414. One of thesubstrate grippers 274, 276 of the robot 268 retrieves the substrate 100from the substrate receiver 410 and removes the substrate 100 from thehousing 402. An optional top spray bar 464 and bottom spray bar 466 arepositioned across the internal volume 412 and may spray the substrate100 with deionized water or any other suitable fluid to clean thesubstrate 100 as the substrate 100 is removed from the particle cleaningmodule 282 by the robot 268. At least one of the spray bars 464, 466 maybe utilized to wet the substrate 100 prior to chucking against thesubstrate receiver 410 to remove particles that may potentially scratchthe backside of the substrate and/or to improve chucking by thesubstrate receiver 410. The spray bars 464, 466 may be coupled todifferent fluid sources 499, 500 so that different fluids may beprovided to each of the spray bars 464, 466, or both spray bars 464, 466may be coupled to a single fluid delivery source.

Referring back to the planarizing module 206 of FIG. 2, both of thesecond and third station 230, 232 may be used to perform CMP process asthe particle cleaning module 282 substantially eliminates the need for abuffing pad disposed in one of the second and third stations 230, 232 asrequired in conventional systems. Since the second and third station,230, 232 are to be used for CMP processes, the use of the particlecleaning module 282 advantageously increases the throughput of the CMPsystem 200. The vertical substrate orientation of the particle cleaningmodule 282 is also beneficial, as it removes particles in a more compactfootprint as compared to traditional horizontal designs utilized on thepolishing module.

Furthermore, the particle cleaning module 282 effectively cleans thesubstrate and decreases the loading of particulate on the brushes of thefirst brush module 264B and second brush module 264C. Therefore, thelifespan of the brushes in the first brush module 264B and second brushmodule 264C are advantageously increased. Thus, the particle cleaningmodule removes particularly difficult to remove polishing fluids withoutrequiring a buffing station in the polishing module and simultaneouslyfrees the second and or third station for additional CMP stations toincrease throughput of the planarizing system.

In some implementations, the driver(s) used to rotate the substrate 100and the actuator used to push the pads and/or polishing film against thesurface of the substrate or edge of the substrate edge may be controlledby the controller 208. Likewise, operation of the fluid delivery nozzles450, 482 may also be under the direction of the controller 208. Thecontroller 208 may be adapted to receive feedback signals from thedriver and/or actuator that indicate: (1) an amount of energy and/ortorque being exerted to drive the substrate 100 (e.g., rotate a vacuumchuck holding the substrate 100) and/or (2) an amount of force appliedto the actuators to push the pads 444, 480 against the substrate 100,respectively. These feedback signals may be employed to determine anamount of material that has been removed from the substrate 100, whichmay include, for example, whether a particular layer of material hasbeen removed and/or whether an intended edge profile has been reached.For example, a reduction in the torque of the rotating substrate 100 (orenergy expended in rotating the substrate 100) during a polishingprocedure may indicate a reduction in friction between the substrate 100and the pad 444, 480. The reduction in torque or rotational energy maycorrespond to an amount of material removed from the edge of thesubstrate 100 at or near points of contact between the substrate 100 andthe pad 444, 480 and/or a characteristic edge profile (e.g., a shape,curvature or smoothness level at the edge of the substrate 100).

Alternatively or additionally, a friction sensor positioned in contactwith the edge of the substrate 100 may provide signals indicative of anamount of material that has been removed from the edge of the substrate100.

In some implementations, the pad 444, 480 may have an adjustable amountof ability to conform to the substrate's edge. In certainimplementations, the pad material may be selected such that the pad 444,480 has an adjustable amount of ability to conform to the substrate'sedge. In certain implementations, the pad 444, 480 may be or include aninflatable bladder such that by adding more air or liquid or otherfluid, the pad becomes harder and by reducing the amount of air orliquid or other fluid in the bladder, the pad becomes more conforming.In some implementations, the fluid supply may inflate/deflate thebladder under the direction of an operator or a programmed and/or useroperated controller. In such implementations, an elastomeric materialsuch as silicon rubber or the like may be used for the bladder tofurther enhance the pad's ability to stretch and conform to thesubstrate's edge. Such an implementation would allow anoperator/controller to precisely control how far beyond the exclusionregion 108 a and/or 108 b and into the bevels 112, 114 (if at all) (SeeFIG. 1) the polishing pad 480 is made to contact the substrate 100 by,e.g., limiting the amount of fluid pumped into the bladder. For example,once a substrate outer edge 110 is placed against the pad 444 with adeflated bladder, the bladder may be inflated so that the pad 444 isforced to wrap around and conform to the outer edge 110 and bevel(s)112, 114 of the substrate 100 without wrapping around to the deviceregion 106 a, 106 b of the substrate 100.

FIG. 8 is a top schematic view of the particle cleaning module 282having a pad conditioning assembly 810 for conditioning the pad 444 anda zero gap calibration sensor having sensor heads 820 a, 820 bpositioned for detecting the position of the pad 444 disposed therein.The particle cleaning module 282 also includes a pair of cleaningnozzles 830 a and 830 b for directing a cleaning fluid (e.g., DI water)toward various components of the particle cleaning module 282 and aspray nozzle 840 for directing a cleaning fluid (e.g., DI water) towardthe polishing pad 480 to condition and remove debris from the polishingpad 480. As depicted in FIG. 11, the second pad actuation assembly 1170does not move in a lateral direction like the second pad actuationassembly 470 depicted in FIG. 4.

The sensor heads 820 a, 820 b of the zero gap calibration sensor may becoupled with the controller 208. The zero gap calibration sensor isconfigured to detect the position of the pad 444 relative to the surfaceof the substrate 100.

FIGS. 9A-9C are schematic views of the first pad actuation assembly 406according to implementations described herein. FIGS. 10A-10D areschematic views of the first pad actuation assembly 406 according toimplementations described herein.

FIG. 9A is a partial schematic view of the particle cleaning module 282where the pad conditioning assembly 810 includes a high pressure spraynozzle 905 for directing a cleaning fluid toward the pad 444 of thefirst pad actuation assembly 406. The pad conditioning assembly 810 ispositioned adjacent to the substrate holder 414 such that the first padactuation assembly 406 may move laterally along rail 458 to the side ofthe substrate holder 414 where the pad 444 may be accessed by the padconditioning assembly 810.

With reference to FIGS. 9B, 9C, 10B, 10C and 10D, the first padactuation assembly 406 includes a first pad holder assembly 910, anadapter 920 for coupling the first pad holder 434 with the first padholder assembly 910. The first pad holder assembly 910 may be coupledwith a motor shaft 925 of the pad rotation mechanism 436. The first padholder assembly 910 may be coupled with the pad rotation mechanism 436via one or more attachment mechanisms 930, for example, clamping screws.The adapter 920 may be coupled with the first pad holder assembly 910via one or more attachment mechanisms 940, for example, a locking pin.The first pad holder 434 may be coupled with the adapter 920 via one ormore attachment mechanisms 950, e.g., a locking screw.

The first pad holder 434 is removable from the adapter 920 forreplacement. In order to replace the pad 444, the attachment mechanism950 only needs to be loosened and the first pad holder 434 and pad 444may be removed without removing the first pad holder assembly 910 andadapter 920. In certain implementations, the first pad holder assembly910 is coupled directly with the first pad holder 434 without the use ofan adapter. A force control mechanism 960 (e.g., a compression spring)may be positioned between the adapter 920 and the first pad holder 434.

FIG. 10A is a schematic perspective view of one implementation of thefirst pad actuation assembly 406. The first pad actuation assembly 406is coupled with the rail 458. As depicted by arrow 1010, the first padactuation assembly 406 is movable along rail 458. The first padactuation assembly 406 is also coupled with a second rail 1030 formovement of the first pad actuation assembly 406 in the direction shownby arrow 1020. Movement in the direction shown by arrow 1020 allows forthe pad 444 to contact the substrate 100 for polishing and cleaning thesubstrate and also allows the pad 444 to contact the pad conditioningassembly 810 for conditioning of the pad 444.

FIG. 11 is a schematic cross-sectional view of another implementation ofa particle cleaning module 1100 according to implementations describedherein. The particle cleaning module 1100 may be used in place of theparticle cleaning module 282 in and of the previously discussedimplementations. Similar to particle cleaning module 282, particlecleaning module 1100 includes a housing 1102, a substrate rotationassembly 404, a first pad actuation assembly 1106 and a second padactuation assembly 1170. However, unlike particle cleaning module 282,the first pad actuation assembly 1106 of particle cleaning module 1100includes a rotary arm assembly 1108 and the second pad actuationassembly 1170 is stationary (e.g. does not move laterally along a tracklike the second actuation assembly 470.) Although the first padactuation assembly 1106 and the second pad actuation assembly 1170 areshown, it should be understood that the implementations described hereinmay be performed with a single pad actuation assembly. For example, thefirst pad actuation assembly 1106 and the second pad actuation assembly1170 may be positioned in separate housings. The housing 1102 includesan opening (not shown) at a top of the housing and a substrate receiver410 at a bottom 1118 of the housing 1102. A drain 1168 is formed throughthe bottom 1118 of the housing 1102 to allow fluids to be removed fromthe housing 1102. The opening allows the robot 268 (not shown in FIG.11) to vertically transfer the substrate to an internal volume 1112defined within the housing 1102. The housing 1102 may optionally includea lid 1104 that can open and close to allow the robot 268 in and out ofthe housing 1102.

The substrate receiver 410 has a substrate receiving slot (not shown inFIG. 11) facing upwards parallel to the Y-axis. The receiving slot issized to accept the perimeter of the substrate 100, thereby allowing theone of the substrate grippers 274, 276 of the substrate handler 266 (SeeFIG. 3) to place the substrate 100 in the receiving slot in asubstantially vertical orientation. The substrate receiver 410 iscoupled to a Z-Y actuator 411. The Z-Y actuator 411 may be actuated tomove the substrate receiver 410 upwards in the Y-axis to align acenterline of the substrate 100 disposed in the substrate receiver 410with a centerline of the substrate rotation assembly 404. Once thecenterline of the substrate 100 is aligned with the centerline of thesubstrate rotation assembly 404, the Z-Y actuator 411 may be actuated tomove the substrate receiver 410 in the Z-axis to contact the substrate100 against the substrate rotation assembly 404, which then actuates tochuck the substrate 100 to the substrate rotation assembly 404. Afterthe substrate 100 has been chucked to the substrate rotation assembly404, the Z-Y actuator 411 may be actuated to move the substrate receiver410 in the Y-axis clear of the substrate 100 and the substrate rotationassembly 404 so that the substrate 100 held by the substrate rotationassembly 404 may be rotated without contacting the substrate receiver410.

The substrate rotation assembly 404 is disposed in the housing 1102 andincludes a substrate holder 414 coupled to a substrate rotationmechanism 416. The substrate holder 414 may be an electrostatic chuck, avacuum chuck, a mechanical gripper or any other suitable mechanism forsecurely holding the substrate 100 while the substrate is rotated duringprocessing within the particle cleaning module 1100. Preferably, thesubstrate holder 414 is either an electrostatic chuck or a vacuum chuck.

The first pad actuation assembly 1106 includes the pad rotationmechanism 436, a pad cleaning head 438, and the rotary arm assembly1108. The pad cleaning head 438 is located in the internal volume 1112of the housing 1102 and includes the first pad holder 434 that holds thepad 444 and a fluid delivery nozzle 450. The fluid delivery nozzle 450is coupled to a fluid delivery source 498 that provides deionized water,a chemical solution or any other suitable fluid to the pad 444 duringcleaning the substrate 100.

The first pad holder 434 (and pad 444) has a diameter much less thanthat of the substrate 100, for example at least less than half thediameter of the substrate or even as much as less than about one eighththe diameter of the substrate. In one implementation, the first padholder 434 (and pad 444) may have a diameter of less than about 25 mm.The first pad holder 434 may hold the pad 444 utilizing clamps, vacuum,adhesive or other suitable technique that allows for the pad 444 toperiodically be replaced as the pad 444 becomes worn after cleaning anumber of substrates 100.

The pad 444 may be fabricated from a polymer material, such as porousrubber, polyurethane and the like, for example, a POLYTEX™ pad availablefrom Rodel, Inc. of Newark, Del. In one implementation, the first padholder 434 may be used to a hold a brush or any other suitable cleaningdevice. The first pad holder 434 is coupled to the pad rotationmechanism 436 by a second shaft 446. The second shaft 446 is orientedparallel to the Z-axis and extends from the internal volume 1112 throughan elongated slit formed through the housing 402 to the pad rotationmechanism 436. The pad rotation mechanism 436 may be an electricalmotor, an air motor, or any other suitable motor for rotating the firstpad holder 434 and pad 444 against the substrate. The pad rotationmechanism 436 is coupled to the controller 208. In one implementation,the pad rotation mechanism 436 rotates the first pad holder 434 (and pad444) at a rate of at least about 1000 rpm.

The pad rotation mechanism 436 is coupled to bracket 454 by an axialactuator 440. The axial actuator 440 is coupled to the controller 208 orother suitable controller and is operable to move the first pad holder434 along the Z-axis to move the pad 444 against and clear of thesubstrate 100 held by the substrate holder 414. The axial actuator 440may be a pancake cylinder, linear actuator or any other suitablemechanism for moving the first pad holder 434 in a direction parallel tothe Z-axis. In operation, after the substrate holder 414 is in contactwith and holding the substrate, the axial actuator 440 drives the firstpad holder 434 in a z-direction to make contact with the substrate 100.

The rotary arm assembly 1108 includes a rotary arm 1180, a rotary armrotation motor 1150, a lateral actuator mechanism 1182 for moving therotary arm 1180 toward the substrate 100. The lateral actuator mechanism1182 may comprise a disk pad arm in/out cylinder coupled 1184 with aspring 1186 for force control and damping.

The second pad actuation assembly 1170 includes a pad rotation mechanism472, and a pad polishing head 474. The pad polishing head 474 is locatedin the internal volume 1112 of the housing 1102 and includes the secondpad holder 478 that holds a pad 480 and a fluid delivery nozzle 482. Thefluid delivery nozzle 482 is coupled to a fluid delivery source 484 thatprovides polishing slurry, deionized water, a chemical solution or anyother suitable fluid to the pad 480 during polishing of the exclusionregion and/or edge region of the substrate 100.

A centerline of the second pad holder 478 may be aligned with the edgeof the substrate 100. The second pad holder 478 (and polishing pad 480)has a diameter much less than that of the substrate 100, for example atleast less than half the diameter of the substrate or even as much asless than about one eighth the diameter of the substrate. In oneimplementation, the second pad holder 478 (and polishing pad 480) mayhave a diameter of less than about 50 mm. The second pad holder 478 mayhold the polishing pad 480 utilizing clamps, vacuum, adhesive or othersuitable techniques that allow for the polishing pad 480 to periodicallybe replaced as the polishing pad 480 becomes worn after polishing theedge of a number of substrates 100.

The polishing pad 480 may be fabricated from a polymer material, such asporous rubber, polyurethane and the like, for example, a POLYTEX™ padavailable from Rodel, Inc, of Newark, Del. The polishing pad 480 may bea fixed abrasive pad. The second pad holder 478 is coupled to the padrotation mechanism 472 by a third shaft 486. The third shaft 486 isoriented parallel to the Z-axis and extends from the internal volume1112 through an elongated slit formed through the housing 1102 to thepad rotation mechanism 472. The pad rotation mechanism 472 may be anelectrical motor, an air motor, or any other suitable motor for rotatingthe second pad holder 478 and polishing pad 480 against the substrate100. The pad rotation mechanism 472 is coupled to the controller 208. Inone implementation, the pad rotation mechanism 472 rotates the secondpad holder 478 (and polishing pad 480) at a rate of at least about 1000rpm.

The pad rotation mechanism 472 is coupled to bracket 488 by an axialactuator 490. The axial actuator 490 is coupled to the controller 208 orother suitable controller and is operable to move the second pad holder478 along the Z-axis to move the polishing pad 480 against and clear ofthe substrate 100 held by the substrate holder 414. The axial actuator490 may be a pancake cylinder, linear actuator or any other suitablemechanism for moving the second pad holder 478 in a direction parallelto the Z-axis. In operation, after the substrate holder 414 is incontact with and holding the substrate, the axial actuator 490 drivesthe second pad holder 478 in a z-direction to make contact with thesubstrate 100.

Scanning the pad 444 across the substrate 100 in the particle cleaningmodule 1100 has effectively demonstrated the ability to effectivelyremove particles, such as abrasives from the polishing fluid, from thesurface of the substrate 100. Further, scanning the polishing pad 480across the exclusion region and/or edge region has demonstrated theability to effectively remove particles, such as abrasives, excessdeposited material, and/or polishing slurry from the surface of thesubstrate 100, for example, the exclusion region and/or edge region ofthe substrate. Thus, the inclusion of a polishing step at the wafer edgein addition to particle cleaning has effectively demonstrated edgedefect improvement. Accordingly, the need for a dedicated buffingstation on the polishing module is substantially eliminated.

FIG. 12 is a cross-sectional schematic view of another implementation ofa disk pad holder according to implementations described herein.

FIG. 13 is another schematic view of the particle cleaning module 1100of FIG. 11 according to implementations described herein. FIG. 13depicts the sweep motion of the rotary arm 1180 along a curved path asshown by arrow 1310.

FIG. 14 is another schematic view of the particle cleaning module 1100of FIG. 11 according to implementations described herein. FIG. 14depicts the sweep motion of the rotary arm 1180 and the attached pad 444along arrow 1310 to interact with the pad conditioning assembly 810 andpad clean spray nozzle 1402 for delivering a cleaning fluid (e.g., DIwater) to surface of the pad 444. A sensor 1404 for detecting thepresence of substrate 100 is positioned on the substrate receiver 410.

FIG. 15 is a schematic view of a portion of a particle cleaning moduleillustrating another implementation of the pad conditioning assembly 810according to implementations described herein. The pad conditioningassembly 810 includes a conditioning pad actuation assembly 1570 forrotating a conditioning pad 1580 and moving the conditioning pad 1580 inan axial direction 1504 toward the pad to be conditioned. Theconditioning pad 1580 may be a conditioning disk. The conditioning padactuation assembly 1570 includes a pad rotation mechanism 1572 and a padpolishing head 1574. The pad polishing head 1574 is located in theinternal volume 1112 of the housing 1102 and includes a pad holder 1578that holds the conditioning pad 1580 and a fluid delivery nozzle 1502.The fluid delivery nozzle 1502 is coupled to a fluid delivery source1584 that provides polishing slurry, deionized water, a chemicalsolution or any other suitable fluid to the conditioning pad 1580 duringconditioning of the pad 444.

FIG. 16 is a schematic view of another implementation of an edge padpolishing assembly 1600 according to implementations described herein.The edge pad polishing assembly 1600 may be used in place of either thesecond pad actuation assembly 470 or the second pad actuation assembly1170. The edge pad polishing assembly 1600 is adjustable between 1 and10 degrees as shown by arrow 1602, which provides better access to theedge of substrate 100 for improved cleaning.

The edge pad polishing assembly 1600 includes a pad rotation mechanism1672, a pad polishing head 1674 and an axial actuator mechanism 1690.The pad polishing head 1674 is located in the internal volume 1112 ofthe housing 1102 and includes an edge pad holder 1678 that holds apolishing pad 1680 and a fluid delivery nozzle. The fluid deliverynozzle is coupled to a fluid delivery source that provides polishingslurry, deionized water, a chemical solution or any other suitable fluidto the polishing pad 1680 during polishing of the exclusion regionand/or edge region of the substrate 100.

A centerline of the edge pad holder 1678 may be aligned with the edge ofthe substrate 100. The edge pad holder 1678 (and polishing pad 1680) hasa diameter much less than that of the substrate 100, for example atleast less than half the diameter of the substrate or even as much asless than about one eighth the diameter of the substrate. In oneimplementation, the edge pad holder 1678 (and polishing pad 1680) mayhave a diameter of less than about 50 mm. The edge pad holder 1678 mayhold the polishing pad 1680 utilizing clamps, vacuum, adhesive or othersuitable techniques that allow for the polishing pad 1680 toperiodically be replaced as the polishing pad 1680 becomes worn afterpolishing the edge of a number of substrates 100.

The polishing pad 1680 may be fabricated from a polymer material, suchas porous rubber, polyurethane and the like, for example, a POLYTEX™ padavailable from Rodel, Inc, of Newark, Del. The polishing pad 1680 may bea fixed abrasive pad. The edge pad holder 1678 is coupled to the padrotation mechanism 1672 by a shaft 1686. The pad rotation mechanism 1672may be an electrical motor, an air motor, or any other suitable motorfor rotating the edge pad holder 1678 and polishing pad 1680 against thesubstrate 100. The pad rotation mechanism 1672 is coupled to thecontroller 208. In one implementation, the pad rotation mechanism 1672rotates the edge pad holder 1678 (and polishing pad 1680) at a rate ofat least about 1000 rpm.

The pad rotation mechanism 1672 may be coupled to a bracket (not shown)by an axial actuator 1690. The axial actuator 1690 is coupled to thecontroller 208 or other suitable controller and is operable to move theedge pad holder 1678 along the Z-axis to move the polishing pad 1680against the edge of the substrate 100 held by the substrate holder 414.The axial actuator 1690 may be a pancake cylinder, linear actuator orany other suitable mechanism for moving the edge pad holder 1678 in adirection parallel to the Z-axis. In operation, after the substrateholder 414 is in contact with and holding the substrate, the axialactuator 1690 drives the edge pad holder 1678 in a z-direction to makecontact with the substrate 100.

While the foregoing is directed to implementations of the presentinvention, other and further implementations of the invention may bedevised without departing from the basic scope thereof, and the scopethereof is determined by the claims that follow.

The invention claimed is:
 1. A particle cleaning module, comprising: ahousing; a substrate holder disposed in the housing, the substrateholder configured to retain a substrate in a substantially verticalorientation, the substrate holder rotatable on a first axis; a first padholder disposed in the housing, the first pad holder having a padretaining surface facing the substrate holder in a parallel and spacedapart relation, the first pad holder rotatable on a second axisrotatable parallel to the first axis; a first actuator operable to movethe first pad holder relative to the substrate holder to change adistance defined between the first axis and the second axis; a secondpad holder disposed in the housing, the second pad holder having a padretaining surface facing the substrate holder in a parallel and spacedapart relation, the second pad holder rotatable on a third axis parallelto the first axis and the second axis; and a rotary arm assembly,comprising: a rotary arm coupled with the first pad holder and operablefor sweeping the first pad holder across a surface of a substrate; and alateral actuator mechanism for moving the rotary arm toward thesubstrate holder.
 2. The particle cleaning module of claim 1, furthercomprising: a third pad holder disposed in the housing, the third padholder having a pad retaining surface for holding a conditioning diskfor conditioning a second pad held by the second pad holder, the thirdpad holder rotatable on a fourth axis parallel to the first axis and thesecond axis.
 3. The particle cleaning module of claim 1, wherein the padretaining surface of the second pad holder is positioned to contact anexclusion region and/or edge portion of a substrate.
 4. The particlecleaning module of claim 3, wherein a centerline of the second padholder is aligned with the exclusion region and/or edge portion of asubstrate positioned on the substrate holder.
 5. The particle cleaningmodule of claim 1, further comprising: a second actuator operable tomove the second pad holder relative to the substrate holder to change adistance defined between the first axis and the third axis.
 6. Theparticle cleaning module of claim 1, further comprising: a substratereceiver disposed in the housing, the substrate receiver having asubstrate receiving slot configured to accept a substrate.
 7. Theparticle cleaning module of claim 6, wherein the substrate receiver isoperable to move between a first position that is aligned with acenterline of the substrate and a second position that is clear of thesubstrate.
 8. The particle cleaning module of claim 1, wherein the firstpad holder has a diameter less than a diameter of the substrate holder.9. The particle cleaning module of claim 1, wherein the second padholder has a diameter less than a diameter of the substrate holder. 10.The particle cleaning module of claim 1, wherein the second pad holderhas a diameter one eighth of a diameter of the substrate holder.
 11. Theparticle cleaning module of claim 1, wherein the substrate holder is anelectrostatic chuck or a vacuum chuck.
 12. The particle cleaning moduleof claim 1, further comprising: a substrate rotation mechanism, operableto rotate the substrate holder about the first axis and coupled to thesubstrate holder by a first shaft.
 13. The particle cleaning module ofclaim 1, further comprising: a plurality of spray bars disposed in thehousing and configured to dispense a cleaning fluid in the housing. 14.The particle cleaning module of claim 1, wherein the housing furthercomprises a lid configured to allow a robot in and out of the housing.15. The particle cleaning module of claim 1, further comprising: apocket coupled to the housing and configured to receive the first padholder.
 16. The particle cleaning module of claim 1, wherein the firstpad holder further comprises a first fluid delivery nozzle.
 17. Theparticle cleaning module of claim 16, wherein the second pad holderfurther comprises a second fluid delivery nozzle.
 18. The particlecleaning module of claim 1, wherein the second pad holder holds afixed-abrasive pad.